1 files changed, 92 insertions, 0 deletions
diff --git a/src/base/atomicio.cc b/src/base/atomicio.cc
new file mode 100644
index 000000000..3f3e6d6f0
--- /dev/null
+++ b/src/base/atomicio.cc
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2008 The Hewlett-Packard Development Company
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Nathan Binkert
+ */
+
+#include <cerrno>
+#include <cstdio>
+
+#include "base/atomicio.hh"
+
+ssize_t
+atomic_read(int fd, void *s, size_t n)
+{
+    char *p = reinterpret_cast<char *>(s);
+    ssize_t pos = 0;
+
+    // Keep reading until we've gotten all of the data.
+    while (n > pos) {
+        ssize_t result = read(fd, p + pos, n - pos);
+
+        // We didn't get any more data, so we should probably punt,
+        // otherwise we'd just keep spinning
+        if (result == 0)
+            break;
+
+        // If there was an error, try again on EINTR/EAGAIN, pass the
+        // error up otherwise.
+        if (result == -1) {
+            if (errno == EINTR || errno == EAGAIN)
+                continue;
+            return result;
+        }
+
+        pos += result;
+    }
+
+    return pos;
+}
+
+ssize_t
+atomic_write(int fd, const void *s, size_t n)
+{
+    const char *p = reinterpret_cast<const char *>(s);
+    ssize_t pos = 0;
+
+    // Keep writing until we've written all of the data
+    while (n > pos) {
+        ssize_t result = write(fd, p + pos, n - pos);
+
+        // We didn't manage to write anything this time, so we should
+        // probably punt, otherwise we'd just keep spinning
+        if (result == 0)
+            break;
+
+        // If there was an error, try again on EINTR/EAGAIN, pass the
+        // error up otherwise.
+        if (result == -1) {
+            if (errno == EINTR || errno == EAGAIN)
+                continue;
+            return result;
+        }
+
+        pos += result;
+    }
+
+    return pos;
+}